Probabilistic graphical models seem to be a very good candidate for a more realistic description of an electric power system. In particular, the factor graphs (FGs) possess a potential to bypass many problems of conventional SE. The algorithm for exact inference on probabilistic graphical models without loops is known as the belief propagation (BP) algorithm [1]}, [2]}. Using BP algorithm, it is possible to efficiently calculate marginal distributions or a mode of the joint distribution of the system of random variables. The BP algorithm can be also applied to graphical models with loops (loopy BP), although in that case, the solution is not guaranteed to converge to correct marginals/modes of the joint distribution.
